This invention relates to an improved process for the addition of liquid perfluoroalkyl iodides to non-halogenated hydrocarbon olefins and non-halogenated hydrocarbon acetylenes. The present invention may be considered to be in a related area of technology as two prior art patents, namely, Brace U.S. Pat. Nos. 3,145,222 and Blanchard et al 3,226,449.
Brace U.S. Pat. No. 3,145,222 discloses perfluoroalkyl iodides can be added to olefins or acetylenes in the presence of free-radical generating catalysts in acceptable conversions and yields. The same reactant materials are disclosed in the present invention. The process of Brace is carried out at temperatures ranging from about 50.degree. to about 190.degree. C, depending primarily upon the specific free-radical generating catalyst that is employed. If the olefin or acetylene employed is a gas at reaction temperature and atmospheric pressure, then a super-atmospheric pressure system must be employed in the practice of the Brace process. This naturally adversely affects the economic feasibility of the process because of the expensive pressure equipment necessary to maintain the conditions and the complication involved thereby. Thus, for example, in order to adjust the concentration of the reactants, the pressure must be adjusted. Safety in operation is also sacrificed by the necessity of working with flammable gas under pressure.
Another teaching in the prior art for obtaining perfluoroalkyl iodide addition products is by a process disclosed in Blanchard et al, U.S. Pat. No. 3,226,449. The patentees disclosed telomerization of perfluoroalkyl iodides with tetrafluoroethylene to obtain higher perfluoroalkyl iodides in the presence of a free radical generating catalyst. This process sets forth injecting tetrafluoroethylene and a free radical generating catalyst during a reaction cycle into liquid perfluoroethyl iodide and mixtures thereof with n-perfluorobutyl iodide which liquid also contains the catalyst in a pressure vessel maintained at a pressure between 225 psi to 700 psi at a temperature of 80.degree. to 170.degree. C. The reaction mixture products are of the structure F(CF.sub.2).sub.m I where m is an even integer from 6 to 12.
The process disclosed by Blanchard et al represents a contribution to the art. However, several inherent limitations exist, namely:
1. Process is limited to a narrow edge of source materials.
2. Process is limited to relatively high pressure conditions involving expensive equipment and inherent hazardous reaction conditions.
3. Process is limited to production of telomers.
In contrast to the prior art teachings, the present process overcomes inherent limitations by its novel aspects and, more specifically, overcomes important disadvantages present in the teachings of Brace et al and Blanchard et al.
It is an object of the present invention to produce a reactant addition product of perfluoroalkyl iodides and gaseous non-halogenated olefins and/or acetylenes which product is formed at or below atmospheric pressure.
It is a further object of the present invention to produce a reactant addition product of perfluoroalkyl iodides and gaseous non-halogenated olefins or acetylenes which reaction product is essentially free of telomers.